1. Field of the Invention
The present invention relates to an organic light emitting display device which may prevent deterioration of luminous efficiency and lifespan.
2. Discussion of the Related Art
Recent transition into an information-oriented society has caused rapid development in the field of displays to visually represent electrical information signals, and correspondingly a variety of flat panel display devices exhibiting excellent properties, such as being thin and lightweight as well as requiring low power consumption, have been developed.
Representative examples of these flat panel display devices may include Liquid Crystal Display (LCD) devices, Plasma Display Panel (PDP) devices, Field Emission Display (FED) devices, and Organic Light Emitting Diode (OLED) display devices.
In particular, organic light emitting display devices are self-illuminating devices, and have faster response speed, higher luminous efficiency and brightness, and wider viewing angle than other flat panel display devices.
Typically, such an organic light emitting display device includes an anode and a cathode arranged to face each other with an emission layer interposed therebetween, such that an electron-hole pair, i.e. an exciton is generated via recombination of a hole injected from the anode and an electron injected from the cathode within the emission layer, and in turn light is emitted via transition of the exciton to the equilibrium state. However, in the typical OLED device, the exciton generated in the emission layer spreads out through the emission layer to interfaces with an electron transport layer and a hole transport layer proximate to the emission layer, which reduces luminous efficiency and causes rapid deterioration of the electron transport layer and the hole transport layer proximate to the emission layer, resulting in reduction of lifespan.